Barriers to an effective HIV / AIDS vaccine
Clinical trials of HIV vaccines have been far fewer, but not so few. They were all unsuccessful. But in one case (published in 2009), a success was announced – protective effectiveness as much as 31% (95% CI 1.7 – 51.8%). Over the next 11 years, it was not even possible to come close to this “achievement”. CombiHIVvac is not a vaccine, but one of many experimental drugs that, when administered to a person, causes the production of antibodies against the antigens contained in the drug. This also applies to “HIV pseudotype neutralizing antibodies” and “cytotoxic T-lymphocytes”.
In principle, there are a great many theoretical options for “designing” drugs that would induce immune responses “to oneself,” and in a modern laboratory they can be made in days / weeks. But to overcome the most serious barriers that an effective vaccine against AIDS must “take” is much more difficult and so far, alas, no one has succeeded. Concisely, these barriers are as follows:
1) Huge variability of HIV. An effective vaccine should protect against any variant of HIV, or at least most. Although promising options appear from time to time in this area, alas, this task has not yet been solved.
2) Having penetrated into the cell, HIV integrates its genome into the cellular genome. An effective vaccine must have time to work in a very short period, when a small enough number of cells are infected with the virus so that all of them could be destroyed by the immune defenses “built up” by the vaccine. If there is at least one cell with an integrated HIV genome, the infection will inevitably take root.
3) The main route of HIV transmission is sexual. An effective vaccine against HIV, in addition to the systemic one, should induce “combat-ready” local immunity (immune defenses in the mucous membranes that serve as “gates” for HIV infection). Apart from live vaccines from an attenuated virus (not an option in the case of HIV), other types of vaccines are ineffective in this regard.
To summarize, the creation of a vaccine against HIV / AIDS is a task of enormous complexity and, in my opinion, it is still very far from its solution.Поділитися цим: